ref: 2d4a2c5c2065a32b6b5bd6a0e887af1574a8dfec dir: /sys/src/ape/lib/ap/gen/abs.c/
#include <stdlib.h> int abs(int a) { if(a < 0) return -a; return a; } long labs(long a) { if(a < 0) return -a; return a; }